scholarly journals Variations of solar UV irradiance related to short-term and medium-term changes of solar activity

1998 ◽  
Vol 103 (A9) ◽  
pp. 20659-20667 ◽  
Author(s):  
O. A. Troshichev ◽  
I. R Gabis
Keyword(s):  
Solar Activity ◽  
Medium Term ◽  
Short Term ◽  
Uv Irradiance ◽  
Solar Uv ◽  
Solar Uv Irradiance

scholarly journals Principal Possibility of the Successful Nowcast and Short-Term Forecast in the Middle Atmosphere Based on the Observed UV Irradiance

2012 ◽  
Vol 2012 ◽  
pp. 1-7
Author(s):  
T. Egorova ◽  
E. Rozanov ◽  
A. V. Shapiro ◽  
W. Schmutz
Keyword(s):  
Climate Model ◽  
Middle Atmosphere ◽  
Satellite Measurements ◽  
Short Term ◽  
Short Term Forecast ◽  
Atmospheric Species ◽  
Term Forecast ◽  
Uv Irradiance ◽  
Solar Uv ◽  
Solar Uv Irradiance

We have applied chemistry-climate model (CCM) SOCOL to simulate the distribution of the temperature and gas species in the upper stratosphere and mesosphere. As an input for the simulation, we employ daily spectral solar UV irradiance measured by SUSIM instrument onboard UARS satellite in January 1992. We have carried out an ensemble of nine 1-month long simulations using slightly different initial states of the atmosphere. We have compared the obtained time evolution of the simulated species and temperature with available satellite measurements. The obtained results allowed us to define the areas where the nowcast and short-term forecast of the atmospheric species with CCM SOCOL could be successful.

Spectral solar UV irradiance data for cycle 21

2001 ◽  
Vol 106 (A10) ◽  
pp. 21569-21583 ◽  
Author(s):  
Matthew T. DeLand ◽  
Richard P. Cebula
Keyword(s):  
Uv Irradiance ◽  
Irradiance Data ◽  
Solar Uv ◽  
Solar Uv Irradiance

scholarly journals SOLAR-v: A new solar spectral irradiance dataset based on SOLAR/SOLSPEC observations during solar cycle 24

2020 ◽  
Vol 645 ◽  
pp. A2
Author(s):  
M. Meftah ◽  
M. Snow ◽  
L. Damé ◽  
D. Bolseé ◽  
N. Pereira ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Spectral Irradiance ◽  
Earth’S Atmosphere ◽  
Solar Spectral Irradiance ◽  
Uv Irradiance ◽  
Solar Cycle 24 ◽  
Solar Uv ◽  
Solar Uv Irradiance ◽  
Cycle 24

Context. Solar spectral irradiance (SSI) is the wavelength-dependent energy input to the top of the Earth’s atmosphere. Solar ultraviolet (UV) irradiance represents the primary forcing mechanism for the photochemistry, heating, and dynamics of the Earth’s atmosphere. Hence, both temporal and spectral variations in solar UV irradiance represent crucial inputs to the modeling and understanding of the behavior of the Earth’s atmosphere. Therefore, measuring the long-term solar UV irradiance variations over the 11-year solar activity cycle (and over longer timescales) is fundamental. Thus, each new solar spectral irradiance dataset based on long-term observations represents a major interest and can be used for further investigations of the long-term trend of solar activity and the construction of a homogeneous solar spectral irradiance record. Aims. The main objective of this article is to present a new solar spectral irradiance database (SOLAR-v) with the associated uncertainties. This dataset is based on solar UV irradiance observations (165−300 nm) of the SOLAR/SOLSPEC space-based instrument, which provides measurements of the full-disk SSI during solar cycle 24. Methods. SOLAR/SOLSPEC made solar acquisitions between April 5, 2008 and February 10, 2017. During this period, the instrument was affected by the harsh space environment that introduces instrumental trends (degradation) in the SSI measurements. A new method based on an adaptation of the Multiple Same-Irradiance-Level (MuSIL) technique was used to separate solar variability and any uncorrected instrumental trends in the SOLAR/SOLSPEC UV irradiance measurements. Results. A new method for correcting degradation has been applied to the SOLAR/SOLSPEC UV irradiance records to provide new solar cycle variability results during solar cycle 24. Irradiances are reported at a mean solar distance of 1 astronomical unit (AU). In the 165−242 nm spectral region, the SOLAR/SOLSPEC data agrees with the observations (SORCE/SOLSTICE) and models (SATIRE-S, NRLSSI 2) to within the 1-sigma error envelope. Between 242 and 300 nm, SOLAR/SOLSPEC agrees only with the models.

scholarly journals Measurements of spectral solar UV irradiance in tropical-Australia

1997 ◽  
Vol 102 (D7) ◽  
pp. 8719-8730 ◽  
Author(s):  
G. Bernhard ◽  
B. Mayer ◽  
G. Seckmeyer ◽  
A. Moise
Keyword(s):  
Uv Irradiance ◽  
Solar Uv ◽  
Tropical Australia ◽  
Solar Uv Irradiance

Variations of UV irradiance at Antarctic station Concordia during the springs of 2008 and 2009

2011 ◽  
Vol 23 (4) ◽  
pp. 389-398 ◽  
Author(s):  
Vito Vitale ◽  
Boyan Petkov ◽  
Florence Goutail ◽  
Christian Lanconelli ◽  
Angelo Lupi ◽  
...  
Keyword(s):  
Spectral Band ◽  
Field Measurements ◽  
Maximum Level ◽  
Ultraviolet B ◽  
Uv Irradiance ◽  
Solar Uv ◽  
Solar Uv Irradiance ◽  
Atmospheric Transmittance ◽  
The Impact ◽  
Ozone Column

AbstractThe features of solar UV irradiance measured at the Italian-French Antarctic Plateau station, Concordia, during the springs of 2008 and 2009 are presented and discussed. In order to study the impact of the large springtime variations in total ozone column on the fraction of ultraviolet B (UV-B) irradiance (fromc.290–315 nm) reaching the Earth surface, irradiance datasets corresponding to fixed solar zenith angles (SZAs = 65°, 75° and 85°) are correlated to the daily ozone column provided by different instruments. For these SZAs the radiation amplification factor varied from 1.58–1.94 at 306 nm and from 0.68–0.88 at 314 nm. The ultraviolet index reached a maximum level of 8 in the summer, corresponding to the typical average summer value for mid latitude sites. The solar irradiance pertaining to the ultraviolet A (UV-A, 315–400 nm) spectral band was found to depend closely on variations of atmospheric transmittance characteristics as reported by previous studies. Model simulations of UV-B irradiance showed a good agreement with field measurements at 65° and 75° SZAs. For SZA = 85° the ozone vertical distribution significantly impacted model estimations. Sensitivity analysis performed by hypothetically varying the ozone distribution revealed some features of the ozone profiles that occurred in the period studied here.

scholarly journals Quality assessment of solar UV irradiance measured with array spectroradiometers

2016 ◽  
Vol 9 (4) ◽  
pp. 1553-1567 ◽  
Author(s):  
Luca Egli ◽  
Julian Gröbner ◽  
Gregor Hülsen ◽  
Luciano Bachmann ◽  
Mario Blumthaler ◽  
...  
Keyword(s):  
Spectral Irradiance ◽  
Stray Light ◽  
Atmospheric Conditions ◽  
End User ◽  
Uv Index ◽  
Uv Irradiance ◽  
The World ◽  
Solar Uv ◽  
Solar Uv Irradiance

Abstract. The reliable quantification of ultraviolet (UV) radiation at the earth's surface requires accurate measurements of spectral global solar UV irradiance in order to determine the UV exposure to human skin and to understand long-term trends in this parameter. Array spectroradiometers (ASRMs) are small, light, robust and cost-effective instruments, and are increasingly used for spectral irradiance measurements. Within the European EMRP ENV03 project “Solar UV”, new devices, guidelines and characterization methods have been developed to improve solar UV measurements with ASRMs, and support to the end user community has been provided. In order to assess the quality of 14 end user ASRMs, a solar UV intercomparison was held on the measurement platform of the World Radiation Center (PMOD/WRC) in Davos, Switzerland, from 10 to 17 July 2014. The results of the blind intercomparison revealed that ASRMs, currently used for solar UV measurements, show a large variation in the quality of their solar UV measurements. Most of the instruments overestimate the erythema-weighted UV index – in particular at large solar zenith angles – due to stray light contribution in the UV-B range. The spectral analysis of global solar UV irradiance further supported the finding that the uncertainties in the UV-B range are very large due to stray light contribution in this wavelength range. In summary, the UV index may be detected by some commercially available ASRMs within 5 % compared to the world reference spectroradiometer, if well characterized and calibrated, but only for a limited range of solar zenith angles. Generally, the tested instruments are not yet suitable for solar UV measurements for the entire range between 290 and 400 nm under all atmospheric conditions.

scholarly journals Dead time effect on the Brewer measurements: correction and estimated uncertainties

2016 ◽  
Vol 9 (4) ◽  
pp. 1799-1816 ◽  
Author(s):  
Ilias Fountoulakis ◽  
Alberto Redondas ◽  
Alkiviadis F. Bais ◽  
Juan José Rodriguez-Franco ◽  
Konstantinos Fragkos ◽  
...  
Keyword(s):  
Solar Irradiance ◽  
Dead Time ◽  
Quality Data ◽  
Data Sets ◽  
Secondary Products ◽  
Uv Irradiance ◽  
Solar Uv ◽  
Operational Algorithm ◽  
The Dead ◽  
Solar Uv Irradiance

Abstract. Brewer spectrophotometers are widely used instruments which perform spectral measurements of the direct, the scattered and the global solar UV irradiance. By processing these measurements a variety of secondary products can be derived such as the total columns of ozone (TOC), sulfur dioxide and nitrogen dioxide and aerosol optical properties. Estimating and limiting the uncertainties of the final products is of critical importance. High-quality data have a lot of applications and can provide accurate estimations of trends.The dead time is specific for each instrument and improper correction of the raw data for its effect may lead to important errors in the final products. The dead time value may change with time and, with the currently used methodology, it cannot always be determined accurately. For specific cases, such as for low ozone slant columns and high intensities of the direct solar irradiance, the error in the retrieved TOC, due to a 10 ns change in the dead time from its value in use, is found to be up to 5 %. The error in the calculation of UV irradiance can be as high as 12 % near the maximum operational limit of light intensities. While in the existing documentation it is indicated that the dead time effects are important when the error in the used value is greater than 2 ns, we found that for single-monochromator Brewers a 2 ns error in the dead time may lead to errors above the limit of 1 % in the calculation of TOC; thus the tolerance limit should be lowered. A new routine for the determination of the dead time from direct solar irradiance measurements has been created and tested and a validation of the operational algorithm has been performed. Additionally, new methods for the estimation and the validation of the dead time have been developed and are analytically described. Therefore, the present study, in addition to highlighting the importance of the dead time for the processing of Brewer data sets, also provides useful information for their quality control and re-evaluation.

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